Lubricating oil



Patented June 6, 1944 UNITED STATES PATENT OFFICE LUBRICATING 01L Bert H. Lincoln, Gordon D. Byrkit, and Waldo L. Steiner, Ponca City, Okla., asslgnors, by name assignments, to Socony-Vacuung Oil Company, Incorporated, New York, N. 2., a corporation of NemYork No 1mm. Application September 15, 1941,

set-1n No. 410,892

during use. It has been found that-the present day hydrocarbon lubricants of the very highest quality are'deflcient in these very important characteristics. These three properties are of vital importance under conditions of thin film the oiliness of these otherwise high quality lubri-r cants. Furthermore, sludge and acid are especially deleterious under conditions of thin film lubrication. The sludge is not a lubricant in any sense of the word, and the soluble acid is particlubrication where the lubricant has been.

squeezed from between the friction surfaces beca se of hi h pressure. slow speeds, and other causes. In modern engines, large surfaces of oil are exposed-to the action of atmospheric oxygen. promoting rapid oxidation. It is readily seen that the viscosity or the body of the lubricant playsno part in thin film lubrication and that the remaining film. of oil must have 'a very high film strength and be of high oiliness value to prevent a rupture of the illm of the lubricant, causing seizure. The oil iilmmust tend to keep the coefllcient of friction as low as possible.

The oil must resist oxidation when these thin films are heated in the presence of atmospheric oxygen as they are in use.

Mechanical devices are being designed for.

to the designer and fabricator of mechanical dethe oiliness or unctuosity of the lubricant is the Y first and primary requisite of emcient operation.

Those skilled in the art of lubricant manufacture or machine'manufacture will readily appreplate the merit of an invention that will improve part of the oiland leave ularly corrosive to hearing metals such as cadmi-. um-siiver. copper-lead,- and the like.

In starting idle mechanical equipment which is lubricated from a sump by pumping or circulating the lubricant, there is always a short period of time in which the rubbing surfaces must operate under conditions of substantially dry friction if ordinary hydrocarbon lubricants are used. With dry friction, the wear on friction surfaces is extreme; andduring cold weather when thelubrfcant is sluggish, or during periods when the lubricating system is not functioningproperly for one reason or another, rubbing surv faces may not only suffer considerable wear but maybe damaged to the point where they must be replaced. The product of our invention has a very important property of reacting with the metal surfaces, penetrating or adsorbing on the metal surfaces, and leaving a film of lubricant with high oiliness character, which remains on the metal surface irrespective of the length of-' time the machine has been idle.

4 The high oiliness film gives very even, and smooth operation, which may be easily discerned by the experienced operator or lubricating engineer.

When the hydrocarbon lubricants are diluted with unburned fuel or with other light hydrocarbons, the small degree of oiliness of the original hydrocarbon lubricant is greatly decreased. We have found that the addition of the products of our invention to hydrocarbon lubricants more than eompensates for the loss in oiliness and load-carrying ability from dilution. It is known that, in order to obtain lubricants which are preeminently satisfactoryfromflhe standpoint of oxidation in use, itis necessary to refine the oil thoroughly and then to add an inhibitor of oxidation. The thorough refining may consist of many and heavy acid treatments or solvent treating sonsto remove aconsiderable {11y the most stable portion. Such drastic refining is necessary in order to obtain stability with respect to sludge formation, but the oil is then easily subject to oxidation to form soluble acids and other corro- 'sive materials. This can be prevented by the addition to the refined oil of small amounts of materials which either prevent the formation of these corrosive products or by some action render them inert. Furthermore, such well-refined oils are susceptible to the formation during use of lacquerlike materials which tend to stick rings. This results in blow-by and hence loss of power, failure of lubrication, scratching, scoring, overheating, and eventually the necessity of replacement of parts. It is practically impossible to refine a lubricant in such a manner as to avoid all three of these difllcu1ties,-namely the formation of soluble corrosive products, sludge, and lacquer. It is considerably more advantageous to add the materials of our invention and thus avoid these difficulties by this method.

Certain compounds are adsorbed or absorbed by metals thus forming tenacious films at the surface of metals; these films are able to stand v high pressures. Investigation by X-ray diffraction methods have shown that compounds con- 'taining highly polar molecules, that is, molecules of unsymmetrical electrical character containing an atom or group of atoms exhibiting a secondary or residual valence, tend to produce regimentation of the molecules of hydrocarbon oil when added thereto. A metal immersed in a strongly polar compound will show a film of the compound in which there is a regimentation of molecules oriented with respect to the surface of the metal by which they are adsorbed or absorbed.

Many of our additive materials are effective when added to poorly refined or even wholly unrefined lubricants. The addends may thus be substituted in whole or in part for the usual refining processes.

In the prior art of applying these principles to the manufacture of lubricants, many diverse types of materials have been suggested to be added to obtain. improvement in various characteristics. It has been found that the addition of various compounds frequently improves film strength, oxidation resistance, noncorrosiveness, and other characteristics.

One object of our invention is'to provide improved inhibitors of oxidation and corrosion .for'

addition to lubricants.

Another object of our invention is to provide sludge and dirt dispersing and suspending agents for use in lubricants and especially in crankcase lubricants.

A further object of our invention is to provide addends which tend to prevent the formation of taminants are kept suspended in the oil by our addends and will not readily settle out. These addends are the metallic salts of partial esters of oxygen-bearing acids of sulfur, selenium, and tellurium, that is, the elements of the right-hand side of group VI of the periodic table. The examples shown below are suitable for use according to our invention:

Metal salts of partial esters of oxygen-bearing acids of sulfur, selenium, and tellurium I. Acids of sulfur A. Sulfurous acid a. Aliphatic Calcium lauryl sulflte, Ca(CnH SO.-s)z b. Oarbocyclic Aluminum cresyl sulfite, ARCH 30081801)! 0. Heterocyclic Mercurous furfuryl sulfltc, llgCrlhODlhSOl B. Sulfuric acid a. Aliphatic Calcium pentacosyl sulfate, Ca(CuH SO)1 b. Carbocyclic Barium naphthyl sulfate, 1324001118001 0. Heterocyclic Thallium III dibenzofurfuryl sulfate,

TKCuH-IOSOOI G. Thlosulfuric acid a. Aliphatic Aluminum cetyl thiosulfatc, AKCIQHJJSiOJ)! b. Carbocyclic Magnesium bcnzyl thlosulfate, Mg(C H CH;S;0;), c. Hcterocyclic Mercuric tetrahydrofurfuryl thiosulfate, MZ(CH10.CH:S50|)1 II. Acids of selenium Aluminum pcntacosyl selenate, AKGnHuSeOOl III. Acids of tellurium,

Aluminum pentacosyl sclenate, Al(CzsHnTe04)| It is to be understood that any of the above metals may be combined with any of the above partial ester radicals to form salts which are suitable for use according to our invention. Furthermore, other metal salts of partial esters of oxygen-bearing acids of sulfur may be used.

These compounds may be added to any type of hydrocarbon lubricants but show an unusual value in highly refined and solvent treated lubricants. The blends prepared in accordance with the present invention are particularly suited for inhibiting corrosion of the new bearing metals,

such as cadmium-silver, copper lead, and the like by such oils.

Byoil having lubricating viscosity in the appended claims, we mean to include the so-called mineral oils andvarious. hydrogenated, polymerized', and otherwise synthetically treated oils, such as volatilized oils, aluminum chloride treated oils, and the like. Furthermore, the lubricating oil may consist in whole or in part of shale oil, animal or vegetable oils, such as castor oil, lard oil, corn oil, cottonseed oil, and the like.

The compounds have varying degrees of solubility in hydrocarbon and other oils. In some cases it is necessary to use a solvent for the compound or to form colloidal suspensions of the compound in oil. While some of these compounds have only limited solubility in hydrocarbon oils, it is to be remembered that because of their great efficiency extremely small amounts are often effective. Thus we have used as little as 0.001 percent of some of these compounds,.and it will be seen that difllcultly soluble material may dissolve to a sufficient extent to be satisfactory for our purpose. In general, more than 0.001 per cent of our addition agents are used, and we may add one, two, or even five per cent or more.

- Furthermore, it is well known that different typesof oils have different capabilities of dissolving a given material. For some purposes therefore, we prefer parafllnic, for other purposes, asphaltic, and for still other purposes, naphthenic or mixed base lubricants. Another method of obtaining a satisfactory mixture of addition agent with the hydrocarbon oil is the'use of a mutual solvent to bring the addend into solution. Alternatively, peptizing agents may be added to maintain. the compounds in permanent suspenit is sometimes advantageous to combine more than one of these compounds in a blend to obtain particular properties. We accomplish this by mixing two or more of these compounds together and blending the mixture with the hydrocarbon oil or by blending one in the hydrocarbon oil, blending the second into this mixture, and so onuntil the composition is complete.

It may be desirable to include in one and the same blend, in addition to the addends here described, other addends for specific purposes. Thus, we may add a pour point depressor such as a naphthalenechlor-wax condensation prodnot, or a viscosity index improver such as certain resins or polymerized hydrocarbons. Furthenn'cre, various metallic compounds may be added to the blend without interfering with the action-of our ingredients. Indeed, in some cases it is advantageous to combine with our compounds in a hydrocarbon oil blend such materials as calcium dichlorstearate, chromium oleate, aluminum steal-ate, and other metallic soaps.

Halogen containing organic compounds and halogenated oxygen bearing ring or aliphatic compounds may be added. The halogen compounds which may thus be employed may be classified as follows:

Classes Examples 1. Open chain compounds:

%iai3$3 a per n wax. HYWM" Chlorinated fractions of hydrocarbon oil. 13. Alcohols Chlorinated octadecsnol 0. Et Dlchloroethyl ether. D. Ketoncs and derivatives.-- Chlorobutyrons. E. Aldehydes and derivatives... octa'gecsnol trichloroace F. Methyl dichlorostcsrste. G. Acids Chloroetearic acid. R. Soc Calcium dlchlorostearstc.

I. Am des. Chlorotolylstearamide. J. Amines hlorosmymm no. K. Ni Chlorinatec; lsurcniiriic L. Suiiur compounds Chloroamy sulfide. M. Phosphorous oompounds. Chlorolanryl phosphite. N. 'Ihlocyanides Chlorolsuryl thiocysnide. 0. Xanthstes and derivatives.. Cbloroamyl amyixsnthate. II. Cyclic compounds: A. Carbocycllo inene hydrochloride. Trichlorobenaene. l. Hydrocarbons Chlorinated naphthalene.

Chlorinated diphenol. Chlorinated cyclohersno. Piglenylrllalted wax co 0 o-Chlorcbenzylsloohoh Dichlorocyciohexancl. 3. Phenols 'Irichlorophenol. 4. Aldehydes-. Cb-orotolusldehyde. 6. K to Ch-crobcnzoplienone. 0. Ch orophenylsteeric acid. 7. Chlorodiphenylcther. 3, Chloronaphthoquinone. 9. Penetachlorophcnyl benzoa 0. Bromobenzamide.

. Ni Cblomxonyl cyanide.

Chlorodiphenyl sulfide. hi Chloracyclcbexyl thiocyans l4. Soaps Calcium, cetyl 3-methyl-,

o-prcpyHfi-endoethyleztig-ci-tetrahydrophthals B. Betsfiocgelle compounds: on

e o-o gen orodi yiene oxide. 2. Hetero-sfiuL.-. Chlorothfit hrene. 3. Hetero-nitrogen- Fluoroquinoline. m. Organo-metsilic compounds Chloroamyl triethyl tin.

Our addends are admirably adapted for use in lubricating oils of all types, including those designed for use in automotive crankcases, Diesel oils, and any other oils of lubricating viscosity. Furthermore, our addends are fivantageously blended in gasoline and other. petroleum fuels either directly or after being blended first in a lubricating oil and then added to the fuel. Soapthickened mineral oils of all types ranging from those showing only a slight increase in viscosity over that of the mineral oil alone to the semisolid and solid greases containing fifty per cent or more of soap are amenable to treatment according to our invention. In making these greases, the usual soaps such as sodium stearate, aluminum stearate, calcium soaps of beta fat, and the like may be used. Various other thickening ingredients or materials for other purposes may be added. These include yarn, hair graphite, glycerol, water, lampblack, mica, zinc dust, litharge, and the like.

The following specific examples of some of our blends are given as illustrations, but we do not wish to be limited thereby:

Example 1 Per cent Mid-Continent SAE 30 98.9 Calcium cetyl sulfite 1.0 Phenyl alpha-naphthylamine .1

Example 2 Mid-Continent SAE 40 98.5 Calcium pentacosyl sulfate 1.5

Example 3 Mid-Continent SAE 20 99.4 Aluminum cetyl thiosulfate .6

Example 4 Steam refined stock 83.2 Raw 150 pale neutral 16.3 Aluminum pentacosyl selenate .5

Example 5 Paraflin base bright stock 45.0 225 pale neutral 54.5 Aluminum pentacosyl tellurate .5

In making a lubricating gasoline, we blend 0.5 per cent of the product of Example 2 with gasoline. It is to be understood, however, that the hydrocarbon oil in the treated fuels may be of a viscosity of from about 35 seconds at degrees Fahrenheit S. S. U. to 350 seconds or more and the amount 01 oil blended with the additive compounds to form the addend may vary between 0 and 99.5 per cent. In some cases the fuel may be prepared without adding any hydrocarbon oil. The quantity of additive compounds in the final blended fuel may vary from 0.001 to 1.0 per cent or slightly more.

It will be understood that certain features and subcombinations may be employed without reference to other species or combinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is therefore to be understood that our invention is not to be limited to the details described.

Having thus described our invention, we claim:

1. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and aminor proportion of a metal salt of aliphatic partial ester of an inorganic oxygen bearing acid of an element selected from the group consisting of sulfur selenium, and tellurium.

3. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of a metal salt of a carbocyclic partial ester of an inorganic oxygen bearing acid of an element selected from the group consisting of sulfur, selenium, and tellurium.

4. A lubricant for metal surfaces comprising in combination a major proportion of, oil of lu-- bricating viscosity and a minor proportion of a metal salt of a heterocyclic partial ester of an inorganic oxygen bearing acid of an element selected from the group consisting of sulfur, selenium, and tellurium.

5. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of a metal salt of a partial ester of an inorganic oxygen bearing acid of sulfur.

6. A lubricant for metal surfaces comprising in combination a major proportion of oil of lu- 9. A lubricant for metal surfaces comprising 45 in combination a major proportion of oil of lubricating viscosity and a minor proportion of ametal salt of a carbocyclic partial ester of an inorganic oxygen bearing acid of sulfur.

10. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of a metal salt of an aliphatic partial ester of thicsulfuric acid.

11. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of a metal salt of a carbocyclic partial ester of thiosulfuric acid. p

12. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of an alkaline earth salt of a partial ester of an inorganic oxygen bearing acidof an element selected from the group consisting of sulfur, selenium, and tellurium.

13. A lubricant for metal surfaces comprising in combination a major proportion of oil of lu;- bricating viscosity and a minor proportion of a calcium salt of a partial ester of an inorganic oxygen bearing acid of an element selected from the group consisting of sulfur, selenium, and tellurium.

14. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of calcium pentacosyl sulfate.

15. A lubricant for metal surfaces comprising in combination a major proportion of oil. of lubricating viscosity and a minor proportion of calcium cetyl sulfite.

16. A lubricant for metal surfaces comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of aluminum pentacosyl thiosulfate.

17. A lubricant for metal surfaces comprising an oil of lubricating viscosity and from 0.001 to 5 per cent of a metal salt of a partial ester of an inorganic oxygen bearing acid of an element selected from the group consisting of sulfur, selenium, and tellurium.

BER-T H. LINCOLN. GORDON D. BYRKIT. WALDO L. STEINER.

bERTIFIcmE OF CORRECTION. Patent No. 2,550,735. June 6, 19bit.

BERT H. LINCOLN, ET AL.

It is hereby "certified that error appears in the printed specification of the above numbered patent requiring correction as fellows Page 5, first column, line 14.9, in the table, for "Chlorinated diphenol" read -Ch1ori nated dipheny].-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of August; A. D. 19141;.-

Leslie Fra zer (Seel) Acting Commissioner of Batents, 

